[HIP] Support attribute hip_pinned_shadow

This patch introduces support of hip_pinned_shadow variable for HIP.

A hip_pinned_shadow variable is a global variable with attribute hip_pinned_shadow.
It has external linkage on device side and has no initializer. It has internal
linkage on host side and has initializer or static constructor. It can be accessed
in both device code and host code.

This allows HIP runtime to implement support of HIP texture reference.

Differential Revision: https://reviews.llvm.org/D62738

llvm-svn: 364381

clang/include/clang/Basic/Attr.td

@@ -295,6 +295,7 @@ class LangOpt<string name, code customCode = [{}]> {
 def MicrosoftExt : LangOpt<"MicrosoftExt">;
 def Borland : LangOpt<"Borland">;
 def CUDA : LangOpt<"CUDA">;
+def HIP : LangOpt<"HIP">;
 def COnly : LangOpt<"COnly", "!LangOpts.CPlusPlus">;
 def CPlusPlus : LangOpt<"CPlusPlus">;
 def OpenCL : LangOpt<"OpenCL">;
@@ -957,6 +958,13 @@ def CUDADevice : InheritableAttr {
   let Documentation = [Undocumented];
 }
 
+def HIPPinnedShadow : InheritableAttr {
+  let Spellings = [GNU<"hip_pinned_shadow">, Declspec<"__hip_pinned_shadow__">];
+  let Subjects = SubjectList<[Var]>;
+  let LangOpts = [HIP];
+  let Documentation = [HIPPinnedShadowDocs];
+}
+
 def CUDADeviceBuiltin : IgnoredAttr {
   let Spellings = [GNU<"device_builtin">, Declspec<"__device_builtin__">];
   let LangOpts = [CUDA];

clang/include/clang/Basic/AttrDocs.td

@@ -4183,3 +4183,15 @@ This attribute does not affect optimizations in any way, unlike GCC's
 ``__attribute__((malloc))``.
 }];
 }
+
+def HIPPinnedShadowDocs : Documentation {
+  let Category = DocCatType;
+  let Content = [{
+The GNU style attribute __attribute__((hip_pinned_shadow)) or MSVC style attribute
+__declspec(hip_pinned_shadow) can be added to the definition of a global variable
+to indicate it is a HIP pinned shadow variable. A HIP pinned shadow variable can
+be accessed on both device side and host side. It has external linkage and is
+not initialized on device side. It has internal linkage and is initialized by
+the initializer on host side.
+  }];
+}

clang/lib/CodeGen/CodeGenModule.cpp

@@ -2415,7 +2415,8 @@ void CodeGenModule::EmitGlobal(GlobalDecl GD) {
       if (!Global->hasAttr<CUDADeviceAttr>() &&
           !Global->hasAttr<CUDAGlobalAttr>() &&
           !Global->hasAttr<CUDAConstantAttr>() &&
-          !Global->hasAttr<CUDASharedAttr>())
+          !Global->hasAttr<CUDASharedAttr>() &&
+          !(LangOpts.HIP && Global->hasAttr<HIPPinnedShadowAttr>()))
         return;
     } else {
       // We need to emit host-side 'shadows' for all global
@@ -3781,7 +3782,12 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
       !getLangOpts().CUDAIsDevice &&
       (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
        D->hasAttr<CUDASharedAttr>());
-  if (getLangOpts().CUDA && (IsCUDASharedVar || IsCUDAShadowVar))
+  // HIP pinned shadow of initialized host-side global variables are also
+  // left undefined.
+  bool IsHIPPinnedShadowVar =
+      getLangOpts().CUDAIsDevice && D->hasAttr<HIPPinnedShadowAttr>();
+  if (getLangOpts().CUDA &&
+      (IsCUDASharedVar || IsCUDAShadowVar || IsHIPPinnedShadowVar))
     Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy));
   else if (!InitExpr) {
     // This is a tentative definition; tentative definitions are
@@ -3892,7 +3898,8 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
       // global variables become internal definitions. These have to
       // be internal in order to prevent name conflicts with global
       // host variables with the same name in a different TUs.
-      if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()) {
+      if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
+          D->hasAttr<HIPPinnedShadowAttr>()) {
         Linkage = llvm::GlobalValue::InternalLinkage;
 
         // Shadow variables and their properties must be registered
@@ -3916,6 +3923,7 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
     }
   }
 
+  if (!IsHIPPinnedShadowVar)
     GV->setInitializer(Init);
   if (emitter) emitter->finalize(GV);
 

clang/lib/CodeGen/TargetInfo.cpp

@@ -7874,12 +7874,24 @@ static bool requiresAMDGPUProtectedVisibility(const Decl *D,
   return D->hasAttr<OpenCLKernelAttr>() ||
          (isa<FunctionDecl>(D) && D->hasAttr<CUDAGlobalAttr>()) ||
          (isa<VarDecl>(D) &&
-          (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()));
+          (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
+           D->hasAttr<HIPPinnedShadowAttr>()));
+}
+
+static bool requiresAMDGPUDefaultVisibility(const Decl *D,
+                                            llvm::GlobalValue *GV) {
+  if (GV->getVisibility() != llvm::GlobalValue::HiddenVisibility)
+    return false;
+
+  return isa<VarDecl>(D) && D->hasAttr<HIPPinnedShadowAttr>();
 }
 
 void AMDGPUTargetCodeGenInfo::setTargetAttributes(
     const Decl *D, llvm::GlobalValue *GV, CodeGen::CodeGenModule &M) const {
-  if (requiresAMDGPUProtectedVisibility(D, GV)) {
+  if (requiresAMDGPUDefaultVisibility(D, GV)) {
+    GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
+    GV->setDSOLocal(false);
+  } else if (requiresAMDGPUProtectedVisibility(D, GV)) {
     GV->setVisibility(llvm::GlobalValue::ProtectedVisibility);
     GV->setDSOLocal(true);
   }

clang/lib/Driver/ToolChains/HIP.cpp

@@ -170,9 +170,8 @@ void AMDGCN::Linker::constructLldCommand(Compilation &C, const JobAction &JA,
                                           const char *InputFileName) const {
   // Construct lld command.
   // The output from ld.lld is an HSA code object file.
-  ArgStringList LldArgs{"-flavor",    "gnu", "--no-undefined",
+  ArgStringList LldArgs{
-                        "-shared",    "-o",  Output.getFilename(),
+      "-flavor", "gnu", "-shared", "-o", Output.getFilename(), InputFileName};
-                        InputFileName};
   SmallString<128> LldPath(C.getDriver().Dir);
   llvm::sys::path::append(LldPath, "lld");
   const char *Lld = Args.MakeArgString(LldPath);

clang/lib/Sema/SemaDeclAttr.cpp

@@ -6786,6 +6786,10 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,
   case ParsedAttr::AT_CUDAHost:
     handleSimpleAttributeWithExclusions<CUDAHostAttr, CUDAGlobalAttr>(S, D, AL);
     break;
+  case ParsedAttr::AT_HIPPinnedShadow:
+    handleSimpleAttributeWithExclusions<HIPPinnedShadowAttr, CUDADeviceAttr,
+                                        CUDAConstantAttr>(S, D, AL);
+    break;
   case ParsedAttr::AT_GNUInline:
     handleGNUInlineAttr(S, D, AL);
     break;

clang/test/AST/ast-dump-hip-pinned-shadow.cu

@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -fcuda-is-device -ast-dump -ast-dump-filter tex -x hip %s | FileCheck -strict-whitespace %s
+// RUN: %clang_cc1 -ast-dump -ast-dump-filter tex -x hip %s | FileCheck -strict-whitespace %s
+struct textureReference {
+  int a;
+};
+
+// CHECK: HIPPinnedShadowAttr
+template <class T, int texType, int hipTextureReadMode>
+struct texture : public textureReference {
+texture() { a = 1; }
+};
+
+__attribute__((hip_pinned_shadow)) texture<float, 1, 1> tex;

clang/test/CodeGenCUDA/hip-pinned-shadow.cu

@@ -0,0 +1,23 @@
+// REQUIRES: amdgpu-registered-target
+
+// RUN: %clang_cc1 -triple amdgcn -fcuda-is-device -std=c++11 -fvisibility hidden -fapply-global-visibility-to-externs \
+// RUN:     -emit-llvm -o - -x hip %s | FileCheck -check-prefixes=HIPDEV %s
+// RUN: %clang_cc1 -triple x86_64 -std=c++11 \
+// RUN:     -emit-llvm -o - -x hip %s | FileCheck -check-prefixes=HIPHOST %s
+
+struct textureReference {
+  int a;
+};
+
+template <class T, int texType, int hipTextureReadMode>
+struct texture : public textureReference {
+texture() { a = 1; }
+};
+
+__attribute__((hip_pinned_shadow)) texture<float, 2, 1> tex;
+// CUDADEV-NOT: @tex
+// CUDAHOST-NOT: call i32 @__hipRegisterVar{{.*}}@tex
+// HIPDEV: @tex = external addrspace(1) global %struct.texture
+// HIPDEV-NOT: declare{{.*}}void @_ZN7textureIfLi2ELi1EEC1Ev
+// HIPHOST:  define{{.*}}@_ZN7textureIfLi2ELi1EEC1Ev
+// HIPHOST:  call i32 @__hipRegisterVar{{.*}}@tex{{.*}}i32 0, i32 4, i32 0, i32 0)

clang/test/Driver/hip-toolchain-no-rdc.hip

@@ -37,7 +37,7 @@
 // CHECK-SAME: "-filetype=obj"
 // CHECK-SAME: "-mcpu=gfx803" "-o" [[OBJ_DEV_A_803:".*-gfx803-.*o"]]
 
-// CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_A_803:.*out]]" [[OBJ_DEV_A_803]]
 
 //
@@ -65,7 +65,7 @@
 // CHECK-SAME: "-filetype=obj"
 // CHECK-SAME: "-mcpu=gfx900" "-o" [[OBJ_DEV_A_900:".*-gfx900-.*o"]]
 
-// CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_A_900:.*out]]" [[OBJ_DEV_A_900]]
 
 //
@@ -109,7 +109,7 @@
 // CHECK-SAME: "-filetype=obj"
 // CHECK-SAME: "-mcpu=gfx803" "-o" [[OBJ_DEV_B_803:".*-gfx803-.*o"]]
 
-// CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_B_803:.*out]]" [[OBJ_DEV_B_803]]
 
 //
@@ -137,7 +137,7 @@
 // CHECK-SAME: "-filetype=obj"
 // CHECK-SAME: "-mcpu=gfx900" "-o" [[OBJ_DEV_B_900:".*-gfx900-.*o"]]
 
-// CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_B_900:.*out]]" [[OBJ_DEV_B_900]]
 
 //

clang/test/Driver/hip-toolchain-rdc.hip

@@ -43,7 +43,7 @@
 // CHECK-SAME: "-filetype=obj"
 // CHECK-SAME: "-mcpu=gfx803" "-o" [[OBJ_DEV1:".*-gfx803-.*o"]]
 
-// CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV1:.*out]]" [[OBJ_DEV1]]
 
 // CHECK: [[CLANG]] "-cc1" "-triple" "amdgcn-amd-amdhsa" 
@@ -75,7 +75,7 @@
 // CHECK-SAME: "-filetype=obj"
 // CHECK-SAME: "-mcpu=gfx900" "-o" [[OBJ_DEV2:".*-gfx900-.*o"]]
 
-// CHECK: [[LLD]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV2:.*out]]" [[OBJ_DEV2]]
 
 // CHECK: [[CLANG]] "-cc1" "-triple" "x86_64-unknown-linux-gnu"

clang/test/Misc/pragma-attribute-supported-attributes-list.test

@@ -53,6 +53,7 @@
 // CHECK-NEXT: FlagEnum (SubjectMatchRule_enum)
 // CHECK-NEXT: Flatten (SubjectMatchRule_function)
 // CHECK-NEXT: GNUInline (SubjectMatchRule_function)
+// CHECK-NEXT: HIPPinnedShadow (SubjectMatchRule_variable)
 // CHECK-NEXT: Hot (SubjectMatchRule_function)
 // CHECK-NEXT: IBAction (SubjectMatchRule_objc_method_is_instance)
 // CHECK-NEXT: IFunc (SubjectMatchRule_function)

clang/test/SemaCUDA/hip-pinned-shadow.cu

@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -triple amdgcn -fcuda-is-device -std=c++11 -fvisibility hidden -fapply-global-visibility-to-externs \
+// RUN:     -emit-llvm -o - -x hip %s -fsyntax-only -verify
+// RUN: %clang_cc1 -triple x86_64 -std=c++11 \
+// RUN:     -emit-llvm -o - -x hip %s -fsyntax-only -verify
+
+#define __device__ __attribute__((device))
+#define __constant__ __attribute__((constant))
+#define __hip_pinned_shadow__ __attribute((hip_pinned_shadow))
+
+struct textureReference {
+  int a;
+};
+
+template <class T, int texType, int hipTextureReadMode>
+struct texture : public textureReference {
+texture() { a = 1; }
+};
+
+__hip_pinned_shadow__ texture<float, 2, 1> tex;
+__device__ __hip_pinned_shadow__ texture<float, 2, 1> tex2; // expected-error{{'hip_pinned_shadow' and 'device' attributes are not compatible}}
+                                                            // expected-error@-1{{dynamic initialization is not supported for __device__, __constant__, and __shared__ variables}}
+                                                            // expected-note@-2{{conflicting attribute is here}}
+__constant__ __hip_pinned_shadow__ texture<float, 2, 1> tex3; // expected-error{{'hip_pinned_shadow' and 'constant' attributes are not compatible}}
+                                                              // expected-error@-1{{dynamic initialization is not supported for __device__, __constant__, and __shared__ variables}}
+                                                              // expected-note@-2{{conflicting attribute is here}}